Ethernet has evolved to meet the growing demands of packet-switched networks. It has become the unifying technology enabling communications via the Internet and other networks using the Internet Protocol (IP). Due to its proven low cost, known reliability, and simplicity, the majority of today's Internet traffic starts or ends on an Ethernet connection. This popularity has resulted in a complex ecosystem among carrier networks, enterprise networks, and consumers, creating a symbiotic relationship among its various parts.
Devices that have Ethernet capability include Ethernet physical sublayer (PHY) devices that adhere to an Ethernet standard. Ethernet PHY devices provide management information, which are referred to herein as PHY register data, indicating their status, configuration, control, and other parameters via management data input/output (MDIO)/management data clock (MDC) interfaces. MDIO is also referred to as a serial management interface (SMI), or media-independent interface management (MIIM), and is defined by the IEEE 802.3 Ethernet standard for a media independent interface (MII).